An integrated PABX/LAN system architecture

A PABX-based architecture is proposed for an integrated voice/data system. The system is composed of an ISDN (integrated-service digital network) PABX with a centralized high-speed packet burst switch module (BSM) attached. 2B+D+P channels are linked to terminals through ordinary telephone twisted pairs. The P channel is a high-speed (1.536-Mb/s) packet channel that supports LAN (local area network) services. The 2B+D+P channels are terminated at the BSM. The 2B channels are demultiplexed and connected to the destination terminals through the PABXs switching network. Signalling information on the D channel is also processed by the PABXs central processor. Packet data on the P channel is exchanged through a parallel packet bus (32-Mb/s) in the BSM. A polling mechanism effectively resolves contention problems. A self-routing packet switch that exchanges packets between BSMs can be used to extend the switching capacity to 256 Mb/ps. This configuration provides: (a) unified system management (maintenance and operation); (b) access integration using ordinary twisted pairs; and (c) full utilization of PABXs voice facilities. The system configuration, technological feasibility, system performance, and prototype system implementation are discussed